One or more embodiments of the subject matter described herein relate to data communications and, more particularly, to data communications with wayside rail equipment or appliances.
Rail vehicles such as trains travel along rails of a track. The rail vehicles may travel into systems of tracks commonly referred to as rail yards. The rail yards include several intersecting tracks with switches at the track intersections. A switch is a rail appliance or equipment that alternates positions to direct the rail vehicles along different portions of the track.
The rail yards may include additional appliances or equipment disposed alongside the tracks, such as track signals or monitoring devices. The track signals may include one or more lights to direct operators of the rail vehicles to move or stop the rail vehicles. The monitoring devices include sensors that monitor the rail vehicles for potential problems such as overheated axles or axle bearings.
Some known rail yards include a yard master who monitors the rail vehicles and rail appliances from a centralized location, such as a tower. The yard master may have wireless equipment that allows the yard master to wirelessly communicate with the rail appliances. For example, the yard master may transmit radiofrequency (RF) signals to a track switch to change positions of the switch, to a track signal to change which lights are illuminated, or to a monitoring device to instruct the monitoring device to examine a rail vehicle.
The use of RF signals to communicate with the rail appliances requires relatively costly equipment in the tower and to be provided with the rail appliances. Moreover, the wireless signals transmitted in rail yards located in urban or densely populated areas may be interfered with by other wireless signals transmitted in the area. The interference with the yard RF signals can cause interruption of communication with the rail appliances and/or for commands to the rail appliances to not be delivered.
A need exists for an improved system and method for communicating with rail appliances disposed alongside a track.